Self-consistent matricity model to simulate the mechanical behaviour of interpenetrating microstructures

A self-consistent matricity model has been developed to simulate the mechan ical behaviour of composites with two randomly distributed phases of interp enetrating microstructures. The model is an extension of the self-consisten t model for matrices with randomly distributed inclusions. In addition to t he volume fraction of the phases, the matricity model allows a further para meter of the microstructure, the matricity M of each phase, to be included into the simulation of the mechanical behaviour of composites with interpen etrating microstructures. The model is applied to the calculation of stress -strain curves and strain distribution curves of an Fe/18vol.%Ag-composite as well as to stress-strain curves of a Ag/58vol.%Ni-composite and its vali dity and superiority upon previous models is demonstrated. The matricities of the phases influence the stress-strain behaviour mainly within the bound s between M = 0.3 and M = 0.7. Beyond these bounds, there exists only a min or influence of matricity on the stress-strain behaviour. Good agreement ha s been obtained between experiment and calculation with respect to the comp osites' mechanical behaviour and the matricity model is thus found to repre sent well metal matrix composites with interpenetrating microstructures. Th e matricity model can be applied to describe the mechanical behaviour of ar bitrary microstructures as observed in two phase functionally graded materi als, where the volume fraction as well as the matricity of the phases vary between the extreme values of 0 and 1. (C) 1999 Elsevier Science B.V. All r ights reserved.